U.S. Pat. No. 4,069,737 to J. O. Anderson, Jan. 26, 1976, disclosed is a handheld apparatus representative of a guitar slide rule consisting of only two parts and is complex in nature. A slider allows for changing only between major and minor keys.
U.S. Pat. No. 4,404,886 to V. M. Leonard, Sep. 20, 1983, shows a note reading octave isolator for a keyboard instrument, lacking aid to a multi-stringed instrument.
U.S. Pat. No. 4,537,111 to J. R. Heath, Aug. 19, 1983, disclosed is a note transposer for guitars and other instruments having a plurity of independent slides in a frame holding them parallel; each slider represents a separate string of an instrument.
U.S. Pat. No. 4,969,383 to R. A. Bezeau, Jr., Nov. 13, 1990, discloses a musical scale indicator composed of two cooperating parts. A base is provided having thereon printed information pertaining to a musical instrument and fingering positions. A slidable, clear overlay is slidably connected with the base. The overlay has printed thereon the letter designations for musical tones. The embodiment of a stringed instrument is limited to only the Aeolian, Locrian, Ionian, Dorian, Phrygian, Lydian, and Mixolydian scales and lacks the ability to accommodate alternate instrument tunings. The embodiment of a keyboard is limited to the same seven scales and fails to show the direct relations of the keyboard and stringed instrument.
U.S. Pat. No. 5,029,507 to R. A. Bezeau, Jr., Jul. 9, 1991, shows a chord progression finder relative to U.S. Pat. No. 4,969,383 and is similar in nature showing chord progressions instead of scale progressions.
U.S. Pat. No. 5,386,757 to D. Derrick, Feb. 7, 1995, discloses a musical scale, scale pattern, and chord indicator with a simulated finger board positioned within a display window on housing. Having the graphics on the cover limits the indicator in accommodating alternate tunings. There is no embodiment to accommodate a musical keyboard.
U.S. Pat. No. 5,597,969 to K. K. M. Brauer, Jan. 28, 1997, discloses a music slide ruler reference device and system, comprising of two cooperating parts. First a flattened sleeve having apertures and music data printed thereon for displaying cooperative music data on a second sliding insert.
U.S. Pat. No. 5,644,096 to G. N. Bull, Jul. 1, 1997, discloses a musical computational device comprising of atleast two elements whose positions relative to each other are alterable. Thou providing information for music notation, a keyboard, and a stringed instrument, it is complex and fails to show the direct tonal note relations between the two instruments. Further, having instrument graphics and tonal note letters on the cover tremendously limits the apparatus in regards to alternate instrument tunings.
While each of the prior art devices might help a music student in learning music theory and some will aid them in learning different fingering positions on their instrument, they are complex and limited in nature. What is needed is a freestanding instructional device that is informative, versatile, upgradeable, and visually simple allowing for real-time play. Further, none of the prior art devices have an embodiment that accommodates the ever growing use of non-standard instrument tunings. Even further, none of the prior art devices show the direct tonal relationships of a keyboard and stringed instruments equivalent finger positions. More and more electronic musical instruments are being developed that are tonally arranged as a multi-stringed instrument, having push buttons which are designed to be played as a keyboard.